To fully charge an EV battery, grid network may face issues such as voltage unbalance, cable limit or transformer limit. All those aspects need to be deliberated to ensure stable grid
networks.
1.3 Objectives
EV battery can be recharged through grid connected charger which becoming an extra load that may affect the entire grid system. To fully charge an EV battery, grid network may
face issues such as voltage drop, cable limit and transformer loading need to be deliberated for stable grid network. This project is carried out:
i. To investigate impacts of EV charging on low voltage LV networks such as voltage
drop, cable thermal limit, transformer loading and energy losses. ii.
To propose and study about countermeasure for moderating impacts.
1.4 Scope
This project is expected to study about effects on LV network in Malaysia brought by EV charging for different penetration levels based on several charging patterns. EV was
assumed to be charged connecting through residential grid which also considered as house load. The residential area will only use Low Voltage LV which is lower than 1kV. Those
impacts comprise voltage drop, cable thermal limit, transformer loading and energy losses. Methods for moderating EV charging impacts are proposed and investigated. Open
Distribution System Simulator OpenDSS was used to simulate all cases.
CHAPTER 2
LITERATURE REVIEW
2.1 Theory and Basic Principles
Electric vehicle EV is type of vehicle which driven by electric, uses an onboard battery as supply for electric motor to build propulsion. Differ from conventional and hybrid
vehicles, EV depend totally on electricity to charge batteries. Regenerative braking is technology that help energy to flow back to the battery when brakes. EV does not need to
change gear because the harder the pedal pressed, the motor turns faster and hence drive the vehicle forward. Electric delivery vehicles accelerate faster than conventional vehicles because
electric motor produces high torque at any load. Moreover, EV has no gear changes which made it comparable for urban driving and sometimes even better than diesel vehicles. EV is
ready for a 10-hour working time after charging for overnight. Electric vehicles involve in transportation applications presently are able to move for 100 miles before charging required
[2]. There are several types of EV available in the market recently. There include battery
EV BEV, hybrid EV HEV, plug-in hybrid EV PHEV and neighborhood EV NEV. BEV, also known as the pure electric vehicle, is a type of electric vehicle that must acquire energy
by connecting to an electrical source to drive the vehicle. BEVs typically move for a mileage
range of 100 to 200 miles powered by batteries-fed electric motor. HEV is combination of an internal combustion engine with an electric motor for the propulsion system. The electric
power-train needs for achieving better fuel economy than a conventional gasoline vehicle. HEV does not need to be recharged through electric grid. The vehicle changes to the
electric motor from the ICE once vehicle is warmed; but it will remain on electric power at low speeds for less than 15 mph or about 24 km per hour. The electric motor improves the
HEV to drive in urban for over 600 miles per tank of gasoline with average 88.5 kmh. PHEV is hybrid vehicle that use rechargeable batteries which can be charging by connecting to an
electric power source. A PHEV is similar with HEV because it contains both internal combustion engine and electric motor. PHEV
referred as “extended range electric vehicles” or EREV at times. Most PHEVs have an expected mileage range from 30 to 40 miles on electric
power especially for shorter trips and ICE are appropriate for long journey. NEV is an EV which limited to speed less than 72.5 kmh speed, depending on the local law. NEV is built to
have a 48.5 kmh maximum speed and 3000 pounds maximum loaded weight. It is typically designed for usage in neighborhood as stated in the name [3].
There are a lot of the benefits brought by EV. First, it does not have emissions at the point of use. It means that none of the unwanted gases release while driving an EV. Next, it
brings a quiet driving experience. Since EV is giving a quiet and smooth operation, it has less noise and vibration compared to conventional vehicle which using ICE. Moreover, EV is also
practical and easy to drive since it is not using conventional gear system. Thus, EV is suitable for urban driving. The traffic in urban which comprise a lot of start and stop will definitely
lead regenerative braking of EV in full use. Last but not least, EV can be charged in home with electrical supply, thus avoids driver for queuing at petrol stations and save time [4].
2.2 Review of Previous Related Works
